FIELD OF THE INVENTION
The invention relates to an optoelectronic module for bidirectional optical data transmission, in particular through the use of a single optical fiber, in which a transmit component for emitting radiation, a receive component for receiving radiation, a beam-splitter device with a beam-splitter layer and a radiation-focusing device for focusing radiation are constructed and disposed relative to one another in such a way that during operation of the optoelectronic module at least a portion of radiation emitted by the transmit component is coupled into an optical device, in particular into an optical fiber, coupled optically to the optoelectronic module, and at least a portion of received radiation released from the optical device is coupled into the receive component.
Such a module is disclosed, for example, in Published European Patent Application 0 664 585 A1, in which a transmit and receive module for bidirectional optical message and signal transmission is described. In that known module, a laser chip is disposed on a common carrier between two carrier parts having side surfaces, adjacent the resonator surfaces of the laser chip, which are provided with reflective coatings and are inclined at an angle of 45.degree. to the resonator surfaces. Radiation emitted by the laser chip parallel to the surface of the common carrier is deflected by one of the side surfaces through 90.degree. in the direction of a lens-coupling optical system which is fastened to the carrier part and couples the radiation into an optical fiber. Radiation released from the optical fiber, and to which the reflective coatings and the material of the carrier parts as well as of the common carrier is at least partially transparent, is received by a photodiode disposed below the common carrier. The device, including a laser chip, photodiode, common carrier and carrier parts, is installed in a hermetically sealed metal housing with a window.
The mounting of the individual constituents of an optoelectronic module of such construction is very complicated. It requires a large number of method steps, the adjustment of the individual constituents relative to one another is difficult, and the metal housing is very expensive. Moreover, large reflection losses occur due to the air gap between the lens and the reflective coating.